The model of extrusion tectonics for the accommodation of the Indo\|Asian collis i on requires the presence of large\|scale strike\|slip faults with hundreds of ki lo meters of displacement. Along the western edge of ...The model of extrusion tectonics for the accommodation of the Indo\|Asian collis i on requires the presence of large\|scale strike\|slip faults with hundreds of ki lo meters of displacement. Along the western edge of the Tibetan Plateau, the Kara koram fault, extending ～900[KG*9]km from the central Pamir to western Tibet, ha s been proposed as one of these accommodating faults. At the northern terminus of the Karakoram fault lies the west\|southwest dipping Kongur Shan detachment f ault system. As the two systems have been proposed to be kinematically linked, constraining the amount of slip along the Kongur Shan detachment system helps d etermine the total displacement along the Karakoram fault system. This in turn will co nstrain the applicability of extrusion tectonics models for the Indo\|Asian coll ision. [KH*2] Detailed geologic mapping was conducted in the northern Kongur Shan region along the Gezi River and near the village of Qiake lake. Kinematic indicators f rom rocks directly below the fault, such as rotated crystals, asymmetric boundar y, and S\|C fabrics, show a normal sense of shear. The detachment fault in th e area dips between 35° to 45° to the east. A thin zone of chloritic breccias, a few meters thick, is locally exposed directly below the fault. Mylonitic gneisse s ＞2[KG*9]km thick are present in the footwall. The strike of mylonitic foliat ions c hanges systematically and, together with the domal geometry of a deformed grani tic body, define a gneiss dome in the footwall. Associated with the variation i n the strike of foliation is a systematic change in the trend of the mylonitic l ineation. Their trend is to the west directly below the fault, but changes to the northwest farther away from the fault. Rocks in the footwall of the detachm ent fault are composed of biotite and muscovite schists (quartz, plagioclase, bi otite, muscovite, +/-garnet, +/-epidote), and deformed granitite sills and sh ee t\|like bodies. Preliminary petrologic studies indicate that these rocks have ex perienced upper greenschist to lower amphibolite facies metamorphism.展开更多
The age of alkali rich porphyries in the western margin of Yangtze Platform is 30—50 Ma; the minerals mainly are orthoclase, quartz, plagioclase; the chemical composition is alkali rich [(K 2O+Na 2O)>8%],high ...The age of alkali rich porphyries in the western margin of Yangtze Platform is 30—50 Ma; the minerals mainly are orthoclase, quartz, plagioclase; the chemical composition is alkali rich [(K 2O+Na 2O)>8%],high potash[(K 2O+Na 2O)=5.09%-8.30%]; the content of REE is relatively low, LREE is concentrated, without anomaly of europium; the average initial ratio of 87 Sr/ 86 Sr is 0.7073; the value of δ 34 S similar to that of the meteoritic sulfur; the ratio of Pb isotope corresponds to that of upper mantle; metallogenic types belong to Cu, Mo, Au, Ag, Pb, Zn polymetal mineralization and rare, rare earth metal mineralization.展开更多
The Animaqen ophiolite belt, controlled by the south Kunlunfault zone, represents the location of the ancient plate suture line. Even though the ophiolite sequence has been disrupted by faulting, the ultramafic rocks,...The Animaqen ophiolite belt, controlled by the south Kunlunfault zone, represents the location of the ancient plate suture line. Even though the ophiolite sequence has been disrupted by faulting, the ultramafic rocks, gabbro, diabase and basalt of the Animaqen ophiolite have been proved to be respectively the metamorphic peridotite and the ultramafic cumulate, the mafic cumulate, the sheeted dike and the mafic exrusive rocks of the typical ophiolite suite. The Animaqen ophiolite is a fragment of the Tethys oceanic crust.展开更多
In this research, major and immobile minor and trace elements are used to study the petrology of Yamaghan deposit. Some major elements of least altered samples were used to classify the host rocks and their magma type...In this research, major and immobile minor and trace elements are used to study the petrology of Yamaghan deposit. Some major elements of least altered samples were used to classify the host rocks and their magma type. Considering slight to medium alteration of the host rock, immobile minor and trace elements of more than 110 samples were used to get more confidential results as well. The results show the high accuracy and reliability of the implemented techniques in the study area.展开更多
文摘The model of extrusion tectonics for the accommodation of the Indo\|Asian collis i on requires the presence of large\|scale strike\|slip faults with hundreds of ki lo meters of displacement. Along the western edge of the Tibetan Plateau, the Kara koram fault, extending ～900[KG*9]km from the central Pamir to western Tibet, ha s been proposed as one of these accommodating faults. At the northern terminus of the Karakoram fault lies the west\|southwest dipping Kongur Shan detachment f ault system. As the two systems have been proposed to be kinematically linked, constraining the amount of slip along the Kongur Shan detachment system helps d etermine the total displacement along the Karakoram fault system. This in turn will co nstrain the applicability of extrusion tectonics models for the Indo\|Asian coll ision. [KH*2] Detailed geologic mapping was conducted in the northern Kongur Shan region along the Gezi River and near the village of Qiake lake. Kinematic indicators f rom rocks directly below the fault, such as rotated crystals, asymmetric boundar y, and S\|C fabrics, show a normal sense of shear. The detachment fault in th e area dips between 35° to 45° to the east. A thin zone of chloritic breccias, a few meters thick, is locally exposed directly below the fault. Mylonitic gneisse s ＞2[KG*9]km thick are present in the footwall. The strike of mylonitic foliat ions c hanges systematically and, together with the domal geometry of a deformed grani tic body, define a gneiss dome in the footwall. Associated with the variation i n the strike of foliation is a systematic change in the trend of the mylonitic l ineation. Their trend is to the west directly below the fault, but changes to the northwest farther away from the fault. Rocks in the footwall of the detachm ent fault are composed of biotite and muscovite schists (quartz, plagioclase, bi otite, muscovite, +/-garnet, +/-epidote), and deformed granitite sills and sh ee t\|like bodies. Preliminary petrologic studies indicate that these rocks have ex perienced upper greenschist to lower amphibolite facies metamorphism.
文摘The age of alkali rich porphyries in the western margin of Yangtze Platform is 30—50 Ma; the minerals mainly are orthoclase, quartz, plagioclase; the chemical composition is alkali rich [(K 2O+Na 2O)>8%],high potash[(K 2O+Na 2O)=5.09%-8.30%]; the content of REE is relatively low, LREE is concentrated, without anomaly of europium; the average initial ratio of 87 Sr/ 86 Sr is 0.7073; the value of δ 34 S similar to that of the meteoritic sulfur; the ratio of Pb isotope corresponds to that of upper mantle; metallogenic types belong to Cu, Mo, Au, Ag, Pb, Zn polymetal mineralization and rare, rare earth metal mineralization.
文摘The Animaqen ophiolite belt, controlled by the south Kunlunfault zone, represents the location of the ancient plate suture line. Even though the ophiolite sequence has been disrupted by faulting, the ultramafic rocks, gabbro, diabase and basalt of the Animaqen ophiolite have been proved to be respectively the metamorphic peridotite and the ultramafic cumulate, the mafic cumulate, the sheeted dike and the mafic exrusive rocks of the typical ophiolite suite. The Animaqen ophiolite is a fragment of the Tethys oceanic crust.
文摘In this research, major and immobile minor and trace elements are used to study the petrology of Yamaghan deposit. Some major elements of least altered samples were used to classify the host rocks and their magma type. Considering slight to medium alteration of the host rock, immobile minor and trace elements of more than 110 samples were used to get more confidential results as well. The results show the high accuracy and reliability of the implemented techniques in the study area.
